How to set the proportion of old and new data sets

[foreverfreedown]

I saw on the public account of depth potential energy how to set the ratio between the old and new data sets, but I did not understand his instructions below how to achieve the ratio of the old and new data sets to 9:1, I hope you can help me.
Thanks!

[tuoping]

Hope this would help. It's captured from lib/python3.8/site-packages/deepmd/DataSystem.py